The Mediterranean Sea, a global hotspot for environmental change, is experiencing rising temperatures and acidification that threaten marine biodiversity and ecosystem stability. Sessile and low-motility invertebrates, such as sponges and gastropods, are especially vulnerable to these stressors but also provide valuable models for studying adaptive responses. The MACCIMO project investigates climate-related stress to key Mediterranean taxa under controlled laboratory conditions simulating IPCC-projected temperature and pH shifts. A comprehensive, multidimensional approach combines morphological, physiological, molecular, and microbial community data to capture responses across multiple biological levels. By integrating imaging, omics, and ecological metadata, the project generates a holistic view of organismal resilience and the interplay between host and symbiont responses under environmental stress. These insights are expected to elucidate mechanisms of acclimation and adaptation in benthic invertebrates, contributing to the development of predictive models that forecast species performance under future ocean conditions.